The embodiment relates to a wireless power transfer system.
Generally, various kinds of electronic appliances employ batteries and are driven by using the power charged in the batteries. In this case, the battery of an electron appliance may be exchanged or may be recharged. The electronic appliance may include a contact terminal for making contact with an external charging apparatus in order to charge the battery. That is, the electronic appliance is electrically connected to the charging apparatus through the contact terminal. However, the contact terminal may be exposed to an outside of the electronic appliance, so that the contact terminal may be contaminated or shot-circuited due to moisture. In this case, a contact error may be generated between the contact terminal and the charging apparatus, so that the battery of the electronic appliance may not be charged.
To solve the above-described problems, wireless power transfer (WPT) for wirelessly charging an electronic appliance had been proposed.
The wireless power transmission system, which is a technique of transferring power through space without any wires, maximizes the convenience of supplying power to mobile appliances and digital home appliances.
The wireless power transmission system may save energy through real-time power using control, overcome a spatial restriction on power supply and reduce consuming power by using the recharging of a battery.
A scheme of implementing a wireless power transmission system is typically classified into a magnetic induction scheme and a magnetic resonance scheme. The magnetic induction scheme, which is a contactless energy transmission technique which generates electromotive force at one coil through the medium of a magnetic flux generated by allowing two coils to approach closely to each other and current to flow through the other coil, may utilize a frequency of several hundreds of kHz. The magnetic resonance scheme, which is a magnetic resonance technique which uses an electric or magnetic field without using any electromagnetic waves or electric currents, may have a transmissible distance of several meters or more and use a bandwidth of several tens of MHz.
Meanwhile, a wireless power transfer system includes a wireless power transfer system-charger of wirelessly transmitting power and a wireless power transfer system-receiver of wirelessly receiving power to charge a load such as a battery. In this case, a charging scheme of the wireless power transfer system-receiver, that is, at least one of the magnetic induction scheme and the magnetic resonance scheme is selected and a wireless power transfer system-charger capable of transferring power corresponding to the charging scheme of the wireless power transfer system-receiver is required to be developed.